North Korea's Kim Jong Un is defying naysayers. The untested leader has proved to be shrewd and savvy, consolidating his grip on power and boosting his image.

A North Korean military band in Pyongyang performs in celebration of the… (Kyodo News )

SEOUL — When Kim Jong Un inherited the leadership of North Korea a year ago, he was something of a laughingstock, an overweight rich guy in his 20s with a negligible curriculum vitae and little world experience aside from a stint in a Swiss middle school.

But Kim is defying the naysayers. He has methodically consolidated his grip on power, replacing his late father's loyalists with his own, and endeared himself to the public with an attractive, well-dressed wife and a more modern public image.

With Wednesday's successful launch of a long-range rocket, the 29-year-old Kim can also take credit for putting a satellite into orbit, a feat that long eluded his father and remains a challenge for rival South Korea.

The launch, immediately criticized by the U.S. and other countries as provocative and a threat to regional security, damped outside hopes for a weak North Korea that would be more compliant under the untested leader. The regime in Pyongyang maintains that the satellite was launched for peaceful scientific purposes, but critics say it could be a step toward North Korea building an intercontinental ballistic missile.

Without question, the launch has left Kim, the world's youngest head of state, basking in the most attention he's seen since he took the helm of the impoverished, isolated country after the death of his father, Kim Jong Il, on Dec. 17.

"He's the man of the moment. On the Korean scoreboard, he's like Yuri Gagarin, the man who got into space," said Daniel Pinkston, a Seoul-based analyst with the International Crisis Group, referring to the first manned spaceflight in 1961 by the cosmonaut.

Kim, the youngest son borne by a woman who was more consort than official wife to the late leader, was catapulted from relative obscurity to the head of the succession line after the oldest son, Kim Jong Nam, was arrested trying to enter Japan on a fake passport to visit Disneyland. As a result, the younger Kim had only a few years' grooming to step into the role of successor.

"Considering how many people said he would have stumbled by now, he has done pretty well and even made a couple of smart moves," said Robert Carlin, a former CIA and State Department intelligence analyst specializing in North Korea.

Despite the rocket launch, the younger Kim has moved away from his father's "military first" policy, signaling that he would instead make economic growth his top priority. In his first major policy speech in mid-April, he pledged not to repeat the famine of the 1990s, in which up to 10% of the population perished.

There was also a rare moment of public candor in April, when an earlier rocket broke apart over the Yellow Sea and North Korea acknowledged the failure, gaining some credibility. "They took a lemon and turned it into lemonade," said Carlin.

Kim Jong Un has been out in public far more often than his reclusive father, often showing off the broad, dimpled smile that makes him resemble his grandfather, Kim Il Sung, the nation's founder. And in a break from the secretive past, where the wives, consorts and mistresses of leaders were kept under wraps, Kim often appears with his well-dressed photogenic wife, Ri Sol Ju.

Kim Jong Un has also benefited from quirks of timing. A long-planned makeover of Pyongyang — new apartments, restaurants, an airport terminal and even a "Dophinarium" — was completed this year as part of a celebration timed to the centennial of Kim Il Sung's birth, giving the young leader credit for what, in fact, was done by his father.

"It is positive that he is young. He studied overseas. He knows how people live overseas. I feel more comfortable with him than with older people," said a 22-year-old North Korean woman who gave her name as Kim Eun Jeong. She was interviewed in October in the Chinese border city of Dandong, where she was working.

"People are expecting reform from him," said a 50-year-old woman from Chongjin, who gave her name as Park Jeong Suk. "And we like it that he looks like Kim Il Sung."

In another public relations coup, Kim invited back to Pyongyang for a public reconciliation a Japanese sushi chef, Kenji Fujimoto, who had been a close family friend and wrote a tell-all memoir about the Kim family. As a result, Fujimoto has become something of an overseas spokesman for the regime, giving frequent interviews about how Kim hopes to improve the living standards of North Koreans.

"That was very clever of him," said Ra Jong-yil, a former South Korean ambassador to Japan and leading North Korea expert in Seoul.

So far, reforms have materialized slowly. An anticipated overhaul of the agricultural system that would have allowed collective farmers more independence never got off the ground.